A step for forming a resist pattern on a substrate, which is one of processes for manufacturing a semiconductor device and an FPD substrate, is composed of a series of steps in which a resist film is formed on a substrate such as a semiconductor wafer (hereinafter referred to as “wafer”), the resist film is exposed with the use of a photomask, and thereafter a desired pattern is obtained by performing a developing process. These series of steps has been conventionally performed by a coating and developing apparatus.
For example, a wafer, which has been subjected to a developing process by the developing apparatus, is subjected to a post-baking process, and a resist pattern is formed by developing. Thereafter, a developing liquid and a rinse liquid remaining in the resist film or on a surface thereof are evaporated and removed. This is a thermal process for hardening the resist and for reinforcing contact between the resist and the wafer. This thermal process if performed at a temperature of, e.g., 130° C. to 200° C.
After completion of the post-baking process, the wafer is returned to a cassette (FOUP) of a cassette station. The wafer, which has been processed at a high temperature, is taken out by a heating apparatus, and is housed into the cassette (FOUP) with such a high temperature. In this case, there are problems of heat accumulation in the cassette (FOUP) and/or warp of the wafer caused by a non-uniform temperature decrease in the cassette.
In order to solve the problems, there is conventionally disposed a cooling table (TCP) through which a wafer is transported, between a cassette station and a process station. The cooling table has a plurality of support pins for supporting a substrate thereon, the support pins being capable of being driven by a cylinder or the like. A cooling water circulates inside the cooling table, whereby a substrate placed on the cooling table can be cooled to a predetermined temperature (see, Patent Document 1, for example).
According to the technique described in Patent Document 1, when a wafer of a high temperature which has been subjected to a post-baking process is returned from the process station to the carrier station, the wafer is passed through the transport cooling table so as to decrease the temperature of the wafer. Then, the wafer is housed into the cassette.
In the invention described in Patent Document 1, a resist liquid is applied to a wafer, a circuit pattern of the wafer is exposed by an exposure device, and then the wafer is received by an interface part. Then, after the wafer has been transported to the process station, the wafer is subjected to a heating process. At this time, there is a case in which a cooling apparatus, which is provided in a group G4 of processing apparatuses that are longitudinally arranged, is used as a transport table. In this case, temperatures of the wafers passing through the cooling apparatus are previously adjusted to be uniform, and the wafers are subjected to a process performed by a subsequent processing part.
[Patent Document]
Patent Document: JP11-54428A (paragraph 0027, and FIGS. 1 and 3 to 7)
However, in accordance with the higher efficiency of a process of a processing unit and the acceleration in a processing speed of a transfer apparatus, a recent coating and developing apparatus of a high productivity has to correspond to an exposing apparatus coping with the high productivity, for example, a system capable of processing wafers at a high speed, e.g., capable of processing 180 to 250 wafers per hour. Thus, a lot of efforts are made to reduce a useless time as much as possible.
In the structure of the transport cooling apparatus described in Citation 1, when a wafer is transported to an arm of a transfer apparatus to the cooling table, the wafer is once held by three support pins, and then the wafer is moved downward and cooled. The arm of the transfer apparatus to which the wafer is transferred receives the wafer, which is waiting the timing after it has been cooled and raised by the support pins.
Thus, when the structure described in Patent Document 1, it is necessary to increase the numbers of wafers to be placed on the cooling table, in order to improve the productivity. This requires a lot of reconsiderations of a force for a cooling water and moving axes of the transfer apparatus, and solutions for acquiring a space in which the wafers can be placed.